Stellar population properties for 2 million galaxies from SDSS DR14 and DEEP2 DR4 from full spectral fitting

Johan Comparat, Claudia Maraston, Daniel Goddard, Violeta Gonzalez-Perez, Jianhui Lian, Sofia Meneses-Goytia, Daniel Thomas, Joel R. Brownstein, Rita Tojeiro, Alexis Finoguenov, Andrea Merloni, Francisco Prada, Mara Salvato, Guangtun B. Zhu, Hu Zou, Jonathan Brinkmann

Published 2017-11-17Version 1

We determine the stellar population properties - age, metallicity, dust reddening, stellar mass and the star formation history - for all spectra classified as galaxies that were published by the Sloan Digital Sky Survey (SDSS data release 14) and by the DEEP2 (data release 4) galaxy surveys. We perform full spectral fitting on individual spectra, making use of high spectral resolution stellar population models. Calculations are carried out for several choices of the model input, including three stellar initial mass functions and three input stellar libraries to the models. We study the accuracy of parameter derivation, in particular the stellar mass, as a function of the signal-to-noise of the galaxy spectra. We find that signal to noise ratio per pixel around 20 (5) allow a statistical accuracy on $\log_{10}(M^{*}/M_{\odot})$ of 0.2 (0.4) dex, for the Chabrier IMF. We obtain the galaxy stellar mass function probed by SDSS, eBOSS and DEEP2 for galaxies with $0.2<z<0.8$. We study DEEP2 galaxies selected by their \OII luminosity in the redshift range $0.83<z<1.03$, finding that they have stellar masses with a flat number density in the range $10^9<M/M_{\odot}<10^{11.5}$. We publish all catalogs of properties as well as model spectra of the continuum for these galaxies as a value added catalog of the fourteenth data release of the SDSS. This catalog is about twice as large as its predecessors (DR12) and will hopefully aid a variety of studies on galaxy evolution and cosmology.